Sleep is a state of consciousness defined by specific EEG patterns and a cyclical structure.
It includes two main phases: NREM and REM.
NREM sleep has three stages, each with distinct EEG characteristics, and decreases in duration as the night progresses.
Hypnagogic sensations often occur as you enter Stage 1.
REM sleep, paradoxically, resembles wakefulness on an EEG, but your body is most relaxed.
Dreaming primarily occurs here.
Deprivation of REM leads to REM rebound, where the body prioritizes REM in subsequent cycles.
The sleep/wake cycle is a circadian rhythm, approximately 24 hours long.
Disruptions, like jet lag and shift work, can affect this rhythm, impacting behavior and cognitive function.
Sleep theories suggest roles in memory consolidation and resource restoration.
Disorders like insomnia, narcolepsy, and sleep apnea interrupt healthy sleep, affecting daily performance.
Recognizing the difference between NREM and REM, and understanding sleep's impact on mental processes, is crucial for grasping how biological systems influence behavior and cognition throughout the day and night.
The trap is to assume all sleep stages have the same restorative effects; they don't.
Each stage has unique functions and disruptions affect you differently.